Media session callbacks

Since a video app runs its media session and media controller in the same activity, the media session callbacks
are different from the implementation shown for the
audio app
server/client architecture. There are no service calls, and notifications are handled via the NotificationManager. The following table shows how the various features are controlled in each callback method:

Note: People using the Google Assistant can control your app with voice commands
if you create your MediaSession with the necessary callbacks. The
requirements are explained in the
Google Assistant documentation.